Abstract: A method of forming a coherent acoustic beam in a marine environment includes directing each of a plurality of source nodes deployed in the marine environment to move in a respective stationary orbit, transmitting an acoustic source signal from each source node; operating a first control loop to adjust a position of each of the plurality of source nodes within the marine environment; and operating a second control loop to adjust characteristics of the acoustic source signals transmitted by each of the source nodes to form a coherent acoustic beam in the far field of a transmitting array formed by the plurality of source nodes. An acoustic beamforming system configured to operate in a marine environment is also provided.

Abstract: A method for extending the range of acoustic data communication within a fluid enclosed in a pipe, such as in a production petroleum well. The method includes providing an acoustic transmitter and receiver in the pipe separated by a distance d. The transmitter converts the ith data bit into a propagating waveform in the pipe. The propagating waveform is received by the receiver after traversing the distance d. The received propagating waveform for the given data bit is then compensated for dispersion using an adaptive process to find the best statistical fit between the dispersed signal and the known signal shape.

Abstract: A method for extending the range of acoustic data communication within a fluid enclosed in a pipe, such as in a production petroleum well. The method includes providing an acoustic transmitter and receiver in the pipe separated by a distance d. The transmitter converts the ith data bit into a propagating waveform in the pipe. The propagating waveform is received by the receiver after traversing the distance d. The received propagating waveform for the given data bit is then compensated for dispersion using an adaptive process to find the best statistical fit between the dispersed signal and the known signal shape.

Abstract: A thermoelectric device transfers heat away from or toward an object using the Peltier effect. In some embodiments, the length of at least one thermoelectric element is at least ten times greater than a combined average cross-sectional dimension, orthogonal to the length, of two thermoelectric elements.

Abstract: A thermoelectric device transfers heat away from or toward an object using the Peltier effect. In some embodiments, the length of at least one thermoelectric element is at least ten times greater than a combined average cross-sectional dimension, orthogonal to the length, of two thermoelectric elements.

Abstract: A thermoelectric device transfers heat away from or toward an object using the Peltier effect. In some embodiments, the length of at least one thermoelectric element is at least ten times greater than a combined average cross-sectional dimension, orthogonal to the length, of two thermoelectric elements.

Abstract: A thermoelectric device transfers heat away from or toward an object using the Peltier effect. In some embodiments, the length of at least one thermoelectric element is at least ten times greater than a combined average cross-sectional dimension, orthogonal to the length, of two thermoelectric elements.

Abstract: A method for forming a device, comprising providing a first substrate carrying a first set of components disposed in a first encapsulating layer over the first set of components, providing a second substrate carrying a second set of components disposed in a second encapsulating layer over the second set of components, bonding the first and second substrates and functionally interconnecting at least one of the predefined components in the first set of components with at least one of the components in the second set of components.

Abstract: A method for forming a device, comprising providing a first substrate carrying a first set of components disposed in a first encapsulating layer over the first set of components, providing a second substrate carrying a second set of components disposed in a second encapsulating layer over the second set of components, bonding the first and second substrates and functionally interconnecting at least one of the predefined components in the first set of components with at least one of the components in the second set of components.

Abstract: A tunable Fabry-Perot filter includes an optical cavity bounded by a stationary reflector and a deformable or movable membrane reflector. A second electrostatic cavity outside of the optical cavity includes a pair of electrodes, one of which is mechanically coupled to the movable membrane reflector. A voltage applied to the electrodes across the electrostatic cavity causes deflection of the membrane, thereby changing the length of the optical cavity and tuning the filter. The filter with the movable membrane can be formed by micro device photolithographic and fabrication processes from a semiconductor material in an integrated device structure. The membrane can include an inner movable membrane portion connected within an outer body portion by a pattern of tethers. The tether pattern can be such that straight or radial tethers connect the inner membrane with the outer body. Alternatively, a tether pattern with tethers arranged in a substantially spiral pattern can be used.

Abstract: A pigtail attach system that exhibits little degradation or change in the coupling during curing and minimizes the impact of different thermal expansion coefficients between the fiber and the substrate. It also isolates the fiber-chip connection from external forces transmitted through the fiber by providing a low-moment fiber stake. A cantilever is formed by pigtailing a V-groove fiber array to an optical waveguide chip using index-matched epoxy. Only the endface of the fiber-array and the sidewall of the waveguide chip are involved in the epoxy-bond. The fiber ribbon is staked away from the cantilever to a pedestal structure, which can comprise silicon and/or glass. The fiber ribbon and the layers of the pedestal are attached together using a low-modulus pedestal epoxy.

Abstract: A tunable Fabry-Perot filter includes an optical cavity bounded by a stationary reflector and a deformable or movable membrane reflector. A second electrostatic cavity outside of the optical cavity includes a pair of electrodes, one of which is mechanically coupled to the movable membrane reflector. A voltage applied to the electrodes across the electrostatic cavity causes deflection of the membrane, thereby changing the length of the optical cavity and tuning the filter. The filter with the movable membrane can be formed by micro device photolithographic and fabrication processes from a semiconductor material in an integrated device structure. The membrane can include an inner movable membrane portion connected within an outer body portion by a pattern of tethers. The tether pattern can be such that straight or radial tethers connect the inner membrane with the outer body. Alternatively, a tether pattern with tethers arranged in a substantially spiral pattern can be used.

Abstract: A tunable Fabry-Perot filter includes an optical cavity bounded by a stationary reflector and a deformable or movable membrane reflector. A second electrostatic cavity outside of the optical cavity includes a pair of electrodes, one of which is mechanically coupled to the movable membrane reflector. A voltage applied to the electrodes across the electrostatic cavity causes deflection of the membrane, thereby changing the length of the optical cavity and tuning the filter. The filter with the movable membrane can be formed by micro device photolithographic and fabrication processes from a semiconductor material in an integrated device structure. The membrane can include an inner movable membrane portion connected within an outer body portion by a pattern of tethers. The tether pattern can be such that straight or radial tethers connect the inner membrane with the outer body. Alternatively, a tether pattern with tethers arranged in a substantially spiral pattern can be used.

Abstract: A field effect transistor having a substrate supporting an active layer comprising a Group III-V material. The active layer has a dopant concentration with a source electrode and a drain electrode disposed over and with a gate electrode disposed between the source and drain electrodes in Schottky barrier contact to the active layer. A surface layer portion of the active layer has a negatively charged surface potential disposed between the drain and gate electrodes comprised of said Group III-V material and oxygen. The surface layer portion has a thickness in the range of 25 .ANG. to 35 .ANG.. A layer of passivation material is disposed at least on the surface layer portion of the active layer.

Abstract: A passivation technique which significantly reduces degradation in reverse breakdown voltage characteristics usually introduced by passivation of active regions of field effect transistors is described. The technique uses a surface treatment in a plasma to introduce into the surface an electro-negative species to maintain negative surface potential of the surface subsequent to encapsulation by the passivation material.

Abstract: A coating apparatus and method for coating industrial cutting and turning tools of any desired shape and configuration and the like significantly to improve the tools' working properties. The coating is formed of cubic boron nitride, with a preferred thickness not exceeding ten microns.The coating apparatus includes an rf excited plasma source chamber having a gas feed ring for ionizing a gas admitted into the chamber via the ring. The preferred feedgas is a borazine and benzene vapor mixture. A coating chamber is mounted adjacent to and contiguous with the plasma source chamber via a neck portion. The coating chamber includes a vacuum interlock to permit the entry and removal of a tool transport. At least one vacuum pump is operatively connected to the chamber. Preferably, a plurality of permanent magnets and electron supply filaments are arranged circumferentially about the plasma source chamber. Preferably, the tool transport is rotatable during coating.

Abstract: A coating apparatus and method for coating industrial cutting and turning tools of any desired shape and configuration and the like significantly to improve the tools' working properties. The coating is formed of cubic boron nitride, with a preferred thickness not exceeding ten microns. The coating apparatus includes an rf excited plasma source chamber having a gas feed ring for ionizing a gas admitted into the chamber via the ring. The preferred feed gas is a borazine and benzene vapor mixture. A coating chamber is mounted adjacent to and contiguous with the plasma source chamber via a neck portion. The coating chamber includes a vacuum interlock to permit the entry and removal of a tool transport. At least one vacuum pump is operatively connected to the chamber. Preferably, a plurality of permanent magnets and electron supply filaments are arranged circumferentially about the plasma source chamber. Preferably, the tool transport is rotatable during coating.